Scale and Scope issues in Great Barrier Reef

John Rolfe

Jill Windle

Jeff Bennett

GBR

• Major biodiversity and recreation icon• Large scale

– extends along most of Qld Coast (4 main sections), – 2900 different reefs, – about 6% of area covered by reef

• Extensive scope – Different assets – reef, fish, seagrass, mammals– Different areas – reef, beaches, islands, inner+outer– Different uses – biodiversity, fishing, recreation

Valuation challenges

• Scale challenges– Changes in geographic scope referred to as a scale issue

– Can values estimated at larger scale be transferred to smaller scale and vice versa

– Whole reef → regional areas → local reefs

• Scope challenges – Do values for key reef assets (fish + corals) change

when more GBR assets are considered?• Marine mammals, beaches, seagrass, biodiversity

Scale issues

• Two very separate reasons why small scale may generate higher values than large scale

• Queuing effect means that respondents focus on the task that is offered to them – May assign higher values because issue is first in the

queue – but lower values to following ones– Extrapolating from smaller scale to larger scale may be

problematic– Task is to identify how values at larger scale can be

apportioned

Proximity effect

• Proximity effect would normally generate higher values for closer assets– Values for assets in close proximity may not be

transferable or expandable to full region

• Care has to be taken in offering smaller scale sets because both proximity and queuing effects may be present

Examples from previous studies

• National Audit (van Beuren and Bennett)– Showed significant adjustments between

regional and national frames

• Fitzroy studies (Rolfe, Windle, Bennett)– Showed no significant difference between

values for catchments and subcatchments

Potential tests for scale - 1

Type 1: (the traditional approach)

• Split sample tests for CM conducted at different scales, but …– Difficult to change scale for some types of

attributes – e.g. number of species– May be difficult to make a small scale focus a

realistic choice task (how do respondents frame these)

Question 7: Carefully consider each of the following three options. Suppose options A, F and G were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Quality Recreation

Area of good water visibility

I would choose

Current condition

16,000 sq km

80%

1,500 species

100%

32,000 sq km

75%

254,000 sq km

75%

Condition in 15 years time

Option A

$0 14,000 sq km

70% 1275 species

85% 28,000 sq km

65% 228,000 sq km

65%

Option F

$50 85% 15% better

90% 5% better

75% 10% better

70% 5% better

Option G

$20 80% 10% better

95% 10% better

70% 5% better

75% 10% better

Question 7: Carefully consider each of the following three options. Suppose options A, F and G were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Quality Recreation

Area of good water visibility

I would choose

Current condition

4,000 sq km

80%

1,500 species

100%

8,000 sq km

75%

63,500 sq km

75%

Condition in 15 years time

Option A

$0 3,500 sq km

70% 1275 species

85% 7,000 sq km

65% 55,600 sq km

65%

Option F

$50 85% 15% better

90% 5% better

75% 10% better

70% 5% better

Option G

$20 80% 10% better

95% 10% better

70% 5% better

75% 10% better

Potential tests for scale - 2• Type 2 – making the framing tradeoff explicit –

similar to hypothetical statement

• Not always clear that respondents stick to the frame they are being asked to consider– The Kakadu story – The ‘success’ of BT tests

• Focus on a smaller scale tradeoff, but make it explicit to respondents that the results will be relevant to a wider set

Setting the scale framework• ‘You will now be presented with some tradeoffs

relating to a section of the Great Barrier Reef. We will use the information to help set policy in the whole GBR region, so please keep in mind that your answers need to relevant to the full region’

• You will now be presented with some tradeoffs relating to a section of the GBR. We are dealing with other sections of the GBR separately, so please do not consider issues outside of the section that you are being asked to focus on’

Question 7: Carefully consider each of the following three options. Suppose options A, F and G were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Quality Recreation

Area of good water visibility

I would choose

Current condition

4,000 sq km

80%

1,500 species

100%

8,000 sq km

75%

63,500 sq km

75%

Condition in 15 years time

Option A

$0 3,500 sq km

70% 1275 species

85% 7,000 sq km

65% 55,600 sq km

65%

Option F

$50 85% 15% better

90% 5% better

75% 10% better

70% 5% better

Option G

$20 80% 10% better

95% 10% better

70% 5% better

75% 10% better

Potential tests for scale - 3• Run separate CM experiments at different scales

in the same questionnaire– Full GBR survey– Regional or Local GBR survey

• ‘We are going to present some options for GBR protection in two main formats. First, we will give you some choices focused on the whole GBR. Then we will give you some choices focused on a smaller area within the GBR’.

Issues with the dual survey approach

• Estimate models for the two ‘splits’ separately?

• Estimate models for the two ‘splits’ together by adding a dummy variable to identify the scale?– Coefficient for the dummy variable will identify the

adjustment factor needed to adjust scales– Is it transferable to other contexts where different

scales have not been presented so explicitly to respondents?

Potential tests for scale - 4

• The post-hoc disaggregation approach

• Run single CM experiment over large-scale GBR

• Then ask respondents to disaggregate values over different areas (e.g. regions) using other techniques– Budget framing exercises

Respondents have to allocate values between sections to 100%

Section Description % of values Far North Largely pristine, some impacts from fishing and

indigenous hunting

North High levels of tourism impact on reefs near Cairns, some impacts from agriculture

Central Water quality impacts from agriculture, tourism in Whitsundays, heavy fishing

Southern Water quality impacts from agriculture, heavy fishing

100%

Scope issues

• Possible to scope the GBR in different ways– Coral reefs + fish– Coral reefs + fish + marine mammals– Coral reefs + fish + MM + beaches and

estuaries

• Are values for additional attributes additive?

Input measures• In the GBR, the input measures used to

achieve protection may be very important– Values for protection may depend on how it will be

implemented

• Key input measures to consider– Improving water quality from agriculture– Reducing commercial & recreational fishing – Green zones – Controlling tourism impacts– Climate change measures

Input measures - 2

• Varying relationships between input measures and different attributes – Improving WQ from agriculture better for

estuaries and corals– Reducing fishing better for fish

• Different levels of uncertainty– Fishing and green zones - low– Agricultural WQ – medium– Greenhouse reduction – very high

The labelled approach

• One option is to label the input measures – Allows information about levels of uncertainty

to be associated with the label

Question 6: Carefully consider each of the following three options. Suppose options A, D and E were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Quality Recreation Area affected by poor

water visibility

I would choose

Current

condition 16,000 sq km

80% of total

1,500 species

100%

32,000 sq km

75%

86,000 sq km

25%

Condition in 15 years time

No Change

$0 14,000 sq km

70% 1275 species

85% 28,000 sq km

65% 121,000 sq km

35%

Reduced impacts from agriculture

$300 17,000 (15% better)

1350 (5% better)

32,000 (10% better)

104,000 (5% better)

Controls over fishing and tourism

$125 16,000 (10% better)

1425 (10% better)

30,000 (5% better)

86,000 (10% better)

The attribute approach

• Include other information as attributes– Type of input (control action)– Certainty of achievement

Question 6: Carefully consider each of the following three options. Suppose options A, D and E were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Type of control and certainty

I would choose

Current condition

16,000 sq km

80% of total

1,500 species

100%

32,000 sq km

75%

Condition in 15 years time

Option A

$0 14,000 sq km

70% 1275 species

85% 28,000 sq km

65% Current policy

Option D

$300 17,000 (15% better)

1350 (5% better)

32,000 (10% better)

Expand green zones (85% certain)

Option E

$125 16,000 (10% better)

1425 (10% better)

30,000 (5% better)

Reduce impacts from agriculture

(55% certain)

The shopping basket approach

• First, define improvements by input measure

• Then give choice sets with different combinations of input measures + price– 2 units of WQ + 1 green zone @ $200– 2 units of green zone + 1 fishing restriction @

$300– Total sum of improvements for each alternative can

also be shown on the choice set

Question 6: Carefully consider each of the following three options. Suppose options A, D and E were the only options available, which would you choose?

How much I pay

Area of coral reef in good

health

No. of fish species

Area of seagrass in good health

Type of control and certainty

I would choose

Current condition

16,000 sq km

80% of total

1,500 species

100%

32,000 sq km

75%

Condition in 15 years time

Option A

$0 14,000 sq km

70% 1275 species

85% 28,000 sq km

65% Current policy

Option D

$300 17,000 (15% better)

1350 (5% better)

32,000 (10% better)

1 green zone + 2 fishing resrictions

Option E

$125 16,000 (10% better)

1425 (10% better)

30,000 (5% better)

3 x agricultural water quality + 2 green

zones